Isolated mitochondrion

This article is about an object derived in the laboratory from an in situ, in vivo organelle, namely mitochondrion

Definition

An isolated mitochondrion is an in vitro variant of the mitochondrion; it is a mitochondrion removed from its containing cell, but with the outer mitochondrial membrane still left intact. This is in contrast to a mitoplast (also an in vitro variant of the mitochondrion), where the further step of removing the outer mitochondrial membrane has been taken.

Isolated mitochondria are created deliberately in the laboratory through mitochondrial isolation procedures specifically designed to create isolated mitochondria. Since the process generally starts with several cells and most cells contain several mitochondria, we usually get a lot of isolated mitochondria together, and hence almost always talk about isolated mitochondria in the plural.

Differences with (in situ, in vivo) mitochondria

Item	Value for (in situ, in vivo) mitochondria	Value for isolated mitochondria
Shape	Tubular (cylindrical), i.e., longer in one dimension than the others; the tubular shape plays well with the mitochondrial network.	Isolated mitochondria are closer to spherical. It is believed that the mitochondria shrink along their tubular axis to come close to a spherical shape during the isolation process.
Interconnection	Networked with other mitochondria to form a mitochondrial network.	Not networked with other mitochondria; they're isolated.